Green Sand Under Bogwood

[tomchurchman]

My 2 month old 240l has a playsand substrate, I noticed today while lifting the bogwood to vacuum underneath that there appears to be some kind of green 'stuff' on the sand directly underneath it. Surely it can't be algea because there is no light. By the way it looks a bit like the green produced by decaying (oxidising) copper
Anyone know what this is?

 

[Colin_T]

any chance of a pic?

it could be copper if you have some copper in the wood. Otherwise it could be blue green algae (Cyanobacter). That will grow in dark conditions and feeds off nutrients.

 

[tomchurchman]

No pics I'm afraid, I sucked it all up before I thought of taking a photos!
I've had the bogwood from 'new' for about one month, come to think of it, there was a piece of bogwood that is about a year old and there was nothing unusual under there.
Whats the drawbacks of copper then? will it reduce over time?

 

[Million]

any chance of a pic?

it could be copper if you have some copper in the wood. Otherwise it could be blue green algae (Cyanobacter). That will grow in dark conditions and feeds off nutrients.

Surely it must be BGA, not copper from bogwood?

 

[Colin_T]

if the wood didn't have any copper in or on it then it won't be copper.

High copper levels will kill snails and fish. If the levels are low then the fish will never get whitespot. But they will have a shorter life span as the copper causes damage to their liver and kidneys and puts them under stress.

It was probably just blue green alage.